Lip-reading

Also called Lipreading, Speechreading, Speech reading

Reading speech from the face, why only about a third of English is visible on the lips, and what the rest is filled in with.

What it is

Lip-reading is understanding speech by watching the speaker's mouth, face and body rather than, or as well as, hearing it. Speechreading is the more accurate word, since a good lip-reader is reading the jaw, the cheeks, the eyebrows, the gesture and the context as much as the lips.

The crucial fact is that most of English is not visible. Roughly a third of speech sounds can be told apart on the lips; the rest happen at the back of the mouth or differ only in voicing. P, B and M look identical from the front. So do T, D and N, and K and G do not show at all. A lip-reader is therefore not reading; they are solving a puzzle at speed, using what they can see plus what the sentence is likely to be. That is why it is tiring and why it fails when the topic changes without warning.

Everyone lip-reads a little; hearing people lean on it in a noisy pub without noticing. For a deaf person it is a skill that can be taught and improved, and the UK has a tradition of lip-reading classes for adults that goes back a century.

Who it can help

Adults who have lost hearing after growing up with spoken English, who already know what the words sound like and can match a lip pattern to a word they own. It works with hearing aids and cochlear implants, not instead of them, and the combination of a little sound and a good view of the face is far stronger than either.

It helps deaf children too, but it should never be the whole plan. A child who has never heard the word cannot fill in the two thirds that are invisible, and an education built on lip-reading alone has historically left many Deaf people with poor English and a great deal of exhaustion. The National Deaf Children's Society is careful on this point.

It does not help a person who cannot see the speaker's face clearly, so a deafblind person needs the tactile methods in this library instead, and it is of limited use to someone whose difficulty is understanding language rather than hearing it.

How it works

The visible part of speech is the visemes: the handful of distinct mouth shapes that groups of sounds share. The lip-reader sees a viseme, holds the several candidate sounds in mind, and lets the rest of the word and the sentence decide. Context does the heavy lifting, which is why a lip-reader who knows the topic can follow well and the same person handed an unexpected sentence cannot.

Good conditions matter more than skill. The speaker's face needs to be lit from the front, still, unobstructed and at a distance of a metre or two. Beards, hands, masks and looking down at notes all remove information. Normal speech is easier to read than slow, exaggerated speech, because exaggeration distorts the patterns the lip-reader has learned.

Classes teach the visemes, the strategies for guessing, and the confidence to ask people to repeat or rephrase. They also teach the sentence-level tricks: asking a closed question so the answer is yes or no, and getting the topic first.

Getting started

If you are losing your hearing, find a lip-reading class this week. They are run by qualified teachers through adult education, hearing loss charities and some hospitals, and RNID can point you to one. Two hours a week over a term makes a measurable difference and the classes are also where people meet others in the same position.

If you live or work with someone who lip-reads, the changes are on your side: face them, stop before you speak, keep your mouth clear, and give the topic before the detail. Rephrase rather than repeat. All of this is in Deaf awareness.

Add a fallback. A written note, a phone screen with text on it, or an app that shows live captions covers the sentence that lip-reading did not catch, and having it ready removes the pressure that makes lip-reading harder.

Where to get help

RNID for classes, hearing checks and equipment. Hearing Link for adults who have lost hearing and their families. The National Deaf Children's Society for children. The condition itself is covered under deafness and hearing loss in the Health A-Z, and your GP can refer you to audiology.